code: def size(self, index):
      return 1
  
file_path: fairseq/examples/data2vec/data/image_dataset.py
imports: import logging
  import numpy
  import os
  from typing import Optional, Callable, Set
  import torch
  from torchvision.datasets.vision import VisionDataset
  from torchvision.transforms import ToTensor
  from fairseq.data import FairseqDataset
label_desc: Use image node_id 6 for calling the ImageDataset obj's underlying member method code with example usage: obj.size(index) and returns: int